Laravel 5.4 如何为同一个自定义验证规则使用多个错误消息

不幸的是，Laravel目前没有提供一种具体的方法来直接从属性参数数组添加和调用验证规则.但这并不排除基于Trait和Request使用的潜在友好解决方案.

例如，请在下面找到我的解决方案.

第一件事是等待表单被处理，用抽象类处理表单请求.您需要做的是获取当前的Validator个实例，并防止它在出现任何相关错误时进行进一步验证.否则，将存储验证器实例，并调用稍后创建的自定义用户验证规则函数:

<?php

namespace App\Custom\Validation;

use \Illuminate\Foundation\Http\FormRequest;

abstract class MyCustomFormRequest extends FormRequest
{
    /** @var \Illuminate\Support\Facades\Validator */
    protected $v = null;

    protected function getValidatorInstance()
    {
        return parent::getValidatorInstance()->after(function ($validator) {
            if ($validator->errors()->all()) {
                // Stop doing further validations
                return;
            }
            $this->v = $validator;
            $this->next();
        });
    }

    /**
     * Add custom post-validation rules
     */
    protected function next()
    {
        
    }
}

下一步是创建Trait，它将提供验证当前验证程序实例输入的方法，并处理要显示的正确错误消息:

<?php

namespace App\Custom\Validation;

trait CustomUserValidations
{
    protected function validateUserEmailValidity($emailField)
    {
        $email = $this->input($emailField);

        $user = \App\User::where('email', $email)->first();
        
        if (! $user) {
            return $this->v->errors()->add($emailField, 'Email not found');
        }
        if (! $user->valid_email) {
            return $this->v->errors()->add($emailField, 'Email not valid');
        }

        // MORE VALIDATION POSSIBLE HERE
        // YOU CAN ADD AS MORE AS YOU WANT
        // ...
    }
}

最后，别忘了延长你的MyCustomFormRequest分钟.例如，在你的php artisan make:request CreateUserRequest之后，下面是一个简单的方法:

<?php

namespace App\Http\Requests;

use App\Custom\Validation\MyCustomFormRequest;
use App\Custom\Validation\CustomUserValidations;

class CreateUserRequest extends MyCustomFormRequest
{
    use CustomUserValidations;

    /**
     * Add custom post-validation rules
     */
    public function next()
    {
        $this->validateUserEmailValidity('email');
    }

    /**
     * Determine if the user is authorized to make this request.
     *
     * @return bool
     */
    public function authorize()
    {
        return true;
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array
     */
    public function rules()
    {
        return [
            'email' => 'bail|required|email|max:255|unique:users',
            'password' => 'bail|required',
            'name' => 'bail|required|max:255',
            'first_name' => 'bail|required|max:255',
        ];
    }
}

我希望你能按照我的建议来做.